1. Field of the Invention
This invention relates to the prophylaxis or amelioration of hypertension or life style related diseases, or to the use of conjugated fatty acids, e.g., conjugated linoleic acid (referred to hereinafter as CLA), more particularly to feeds, drinks, foods, health food supplements, and pharmaceuticals which contain the conjugated fatty acids in the form of a free fatty acid, salt, ester fatty acid derivative, or a mixture of the two or more thereof.
2. Background Art
Hypertension refers to blood pressure higher than its normal range, and either of systolic blood pressure of 140 mmHg or more, or diastolic blood pressure of 90 mmHg or more is defined as hypertension (The Japanese Society of Hypertension). Hypertension is divided into secondary hypertension of which the cause has been revealed and essential hypertension caused by genetic or environmental factors. Ninety percent of hypertension is considered to be essential hypertension, in which living factors such as stress, excessive salt intake, overeating, and lack of exercise are strongly involved.
There are now about six hundred million hypertensives in the world, and about three million patients die annually of hypertension as the direct cause of death. It is estimated that the number of hypertensives in Japan reaches about thirty-three millions, which correspond to one-third of the population of the adults. The first rank of the cause of death of Japanese is cancer or malignant tumor, the second rank is cerebral stroke, and the third rank is cardiovascular disease, and the diseases in the second and third ranks are caused primarily by hypertension. Hypertension is the most important risk factor of cerebral stroke, and may cause a variety of circulatory diseases such as cardiovascular diseases, kidney diseases, and arteriosclerosis obliterans. In addition, it has been proved that hypertension is also involved intensively in causing senile dementia. Nowadays when senile populations have been a significant part of the society, it is very important to prevent hypertension in order to anticipate healthy golden years with maintaining QOL (Quality of Life).
Now, it is also possible to remit serious hypertension by developing depressors. Among these agents, Ca-antagonists are the most popularly used in Japan, however these agents may cause tachycardia, palpitatio cordis, or edema. In addition, ACE inhibitors for blocking the action of the renin-angiotensin system which raises blood pressure may cause an unproductive cough.
The prophylaxis or amelioration of hypertension requires the ingestion of a hypotensor over a long period of time, and it is desired to have foods having further regard to safety.
For instance, gamma-aminobutyric acid as a foodstuff exhibits blood pressure lowering effect even at a safe and small dose to allow its ingestion for a long period of time (Japanese Patent Laid-Open Publication No. 10/215,812). However, depressors and drugs, health food supplements, drinks and foods having blood pressure lowering effect have no effect for ameliorating hypertension itself, and thus the original hypertensive state will reappear by the stopping of their administration. In addition, it may enhance the risk of apoplexy or heart diseases that patients discontinue the drug without direction by the physician. Therefore, it is recommended to carry out exercise, diet control, and no smoking, and to make an environment in which no stresses are accumulated, but it is not easy to conduct such countermeasures.
In addition, while the effects of preventing and ameliorating hypertension have been deduced in conjugated trienoic acids (Japanese Patent Laid-Open Publication No. 2002/265985), these effects have not been confirmed, and with regard to CLA as the conjugated dienoic acid, no reports have been described on the influence on blood pressure as far as we know.